No, they don’t sound terribly appetising do they? We need to come up with a different name – but this old traditional one does describe their appearance so well and gives them a certain character. But it gives no hint to their intensity and flavour impact – and the surprise is part of the pleasure maybe.
Leathers are a traditional technique for preserving fruits; made well, they will keep fruits as a snack sweetmeat through the winter. They require a lot less sugar than jam or jelly, and pack more flavour. Made carefully, they don’t need much cooking either and so can keep flavours bright and intense.
We have a ‘duplicated’/mimeograghed copy of fruit preserving leaflet from the 80s in which leathers feature prominently, but it wasn’t until my Wild Wonders course last year that I was re-introduced to their possibility. I struggle with how to manage fruits in the chocolates – they are wet, acidic and often don’t carry intense enough flavour to make a great impact in the ganache. Acquiring a dehydrator has helped – and drying some fruits helps manage the moisture without too much boiling or added sugar; raspberries and sea buckthorn work particularly well in this way.
But leathers offer a way to process fruits and weave round chocolate in a different way from ganache filled chocolates, and I began to play around with them last year. Blaeberries were my first real success; I went to a great talk by Eva Gunnare, a Swedish forager, as part of the Foraging Fortnight and she gave us blueberry leather and described how simple it was to make. You can reduce your fruit pulp by simmering and boiling, but better still – reduce through dehydration. The sugar added can then be more about taste than preservation as you are removing excess water through the dehydrating process not the boiling/simmering/sugar concentration. This is why freezer jams for rasps and strawberries are so delicious – preservation is managed through freezing and not sugar concentration and moisture reduction through boiling – the flavours are fresher, brighter and more intense.
For wet fruits like blaeberries leather making was the answer – get it right and you have a soft, slightly chewy, intensely flavoured nibble – that is just perfect dipped in the right chocolate. We made these for the Wild Food Festival last year and they disappeared really quickly.
They are though, a lot of work. Foraging wild fruits is in itself a labour requiring meditative levels of patience and endurance. Blaeberries, raspberries, wild strawberries (actually I have never gathered enough of these at any one time to do anything other than eat them!) – but the joy of leathers is that you can make from any fruit or vegetable I imagine. So we have tried rhubarb, Japanese knotweed, elderberries and sloes.
I cannot really give you a recipe, more like a process. So much depends on the fruit, the flavour you want, and what equipment you have for dehydrating. I will describe the process for raspberries and blaeberries, and hope that this serves as enough of a guide to help you get started.
Pick over your fruit to remove any mouldy or badly damaged fruits; remove stalks and leaves. Wash carefully and drain. Weigh the fruit, and add a third of that weight in sugar (less if you think the fruit already sweet). Mix in and leave covered for a few hours – stirring occasionally to help bring out the juice. By the end of this period, there should be lots of juice, possibly submerging all the fruit.
Quickly bring to the boil, just to kill off any bacteria or yeasts; if you don’t mind the seeds, then mush up into a pulp. Otherwise strain into a bowl; using the back of a metal spoon, force as much of the juice and soft fruit pulp through the sieve, until you have only seeds and skin in the sieve. If the strained liquid is really thin, you could heat and evaporate off some of the excess water – but be careful about monitoring the taste, as this will change with prolonged cooking.
Prepare trays to go in the dehydrator – maybe line with silicon baking paper, and pour a thin layer of the pulp (say 0.5 to 1cm deep – depending on how thick you would like your leather to be; remember it will shrink considerably through drying so take this into account *).
Dehydrate on a low heat – 115 to 120 F – until tacky enough to handle. Remove from the paper, peeling it away carefully. To store, lay the sheet onto fresh paper and then roll up with the paper so that there is sheet of paper between each layer of the leather. Wrap in a plastic bag, or in a sealed food box. When you want to use, unroll and cut into strips.
*I tried making a rhubarb leather once that was too thin and it dehydrated to hand-made paper thinness – infact thinking about it, it was hand made paper – edible and beautiful pink green mottled colouring. OK – a whole new possible craft industry – edible fruit papers!